Research Article

Movement patterns of juvenile and adult noble crayfish (Astacus astacus) in a small stream, determined by radiotelemetry

¹ T.G. Masaryk Water Research Institute, p.r.i.; Podbabská 2582/30, 160 00 Prague, Czech Republic
² Norwegian Institute of Nature Research; Fakkelgården, 2624 Lillehammer, Norway

^* Corresponding author: tomas-danek@centrum.cz

Received: 22 May 2019
Accepted: 9 September 2019

Abstract

This article reports on the results of the first radiotelemetric field study comparing the movement patterns of juvenile and adult noble crayfish (Astacus astacus) over the 24-h cycle. During our study (in summer, outside the reproduction period), juveniles moved over significantly longer distances than adults; upstream movements prevailed in both groups. The longest distance covered by an individual crayfish during a three-hour interval was 110 m (in the upstream direction). Adults moved most frequently at dusk and least frequently during daytime. Among juveniles, the likelihood of movement did not significantly differ between the times of day; however, distances covered by juveniles were the longest at night and significantly shorter during daytime and at dusk. Juveniles and adults exhibited very similar local activity (motion within a single place) with high values at night and low values during daytime.